Answer this question truthfully
### Question: What causes Otitis externa?
### Response: Otitis externa is caused by sources of inflammation to the external ear:
Bacterial and fungal infections from trapped water in the ear canal. Spread of skin conditions such as eczema. Allergies. Excessive or abrasive use of cotton swabs, Q-tips etc. that scratch and damage the skin of the ear canal. Growth of the bone in the ear canal from persistent water pressure (also known as surfer's ear). Chemical irritants in cosmetic products, such as soaps or shampoos. Lack of earwax from excessive cleaning. Prolonged exposure to excessive humidity. A weakened immune system in the case of malignant otitis externa.